Noise Abatement Departure Procedures (NADPs)

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Revised National Business Aviation Association (NBAA) Noise Abatement Departure Procedures (NADPs) Presentation to: Noise Compatibility Committee October 29, 2015 Ted Baldwin 2 What are NADPs?  Departure procedures designed to minimize noise, by:  Adjusting power settings, rates of climb, speeds, etc.  Cutting thrust at defined altitudes and speeds  NBAA is a leader in promoting NADPs for g.a. jets  Until October 2014, NBAA recommended two NADP options  “Close-In” where there are sensitive land uses within two miles of the runway end (this is the recommended procedure at APF)  “Standard” where sensitive land uses generally start beyond two miles from the runway end  In October 2014 NBAA published revised NADP options  Retain the “Standard” procedure  Add a new “High Density Airport” procedure  Eliminate the “Close-In” procedure 3 Why did NBAA develop revised NADPs?  To address the general aviation jet fleet operating today  Former NADPs were designed for models operating in the late 1970s • Stage 1 and 2 models, and the earliest Stage 3 models, such as the Lear 35 • 84% of jets operating at APF in January - March 2015 met Stage 4 or 5  Manufacturers, operators, pilots, and airports came to realize that the procedures were counterproductive in many cases  To address the increasingly congested air traffic environment at “high-density” airports, where NADPs can:  Conflict with minimum speed and climb criteria for use of Performance- Based Navigation (PBN) procedures  Raise concerns about maintaining safe aircraft separation at airports in areas with a high density of flight traffic 4 How do the procedures compare? NBAA requested analysis of three aircraft models  Learjet 35 - mid-1970s technology  Small cabin business jet falling between Stage 4 and 5 standards  Typical takeoff weight 18,000 pounds  Gulfstream IV (GIV) - mid-1980s technology  Large cabin business jet meeting Stage 5 standards  Typical takeoff weight 75,000 pounds  Cessna Citation X (C750) - mid-1990s technology  Medium cabin business jet significantly quieter than Stage 5 standards  Typical takeoff weight 36,000 pounds  Sound exposure level (SEL) contours prepared for a sea-level airport at 59°F (“standard day conditions”) Major conclusion: Aircraft technology is far more important than the procedure used. 5 How do the procedures compare? All three procedures for the Lear 35 Observation: Differences are complex and benefit depends on location. 6 How do the procedures compare? All three procedures for the GIV Observation: Differences are complex and benefit depends on location. 7 How do the procedures compare? All three procedures for the Citation X Observation: Close-in is very similar to standard. 8 These slides will be used only if needed to answer questions. 9 How do the procedures compare? Noise metric used  Sound Exposure Level (SEL) noise analysis  Measure of total noise energy during an aircraft flyover  Part 150 requires its use in noise modelling  We have used in prior noise studies at APF SEL = 108 dBA 10 How do the procedures compare? Major procedure steps are complex Step Standard High Density Close-In Brake release Takeoff flaps and thrust Lift off Max. practical climb rate to 1,000’ ≤ V2+20 Max. practical climb rate to 800’ ≤ V2+20 Max. practical rate of climb to 500’ at V2+20 Thrust cutback climb segment At 1,000’, accelerate to Vfs, retract flaps, reduce to quiet climb power, maintain 1,000 FPM climb and maximum 190 knot airspeed At 800’, accelerate to Vfs, retract flaps, reduce to quiet climb power, maintain 1,000 FPM climb and maximum 190 knot airspeed At 500’, reduce to quiet climb power, maintain 1,000 FPM climb and V2+20 knots At 1,000’, accelerate to Vfs, retract flaps, maintain quiet climb power, 1,000 FPM, and maximum 190 knots Resume normal climb At 3,000’ At 1,500’ At 1,000’  Altitudes are feet above airport elevation (AAE)  Vfs is final segment speed, based on one engine out climb, clean configuration, and max. continuous power  FPM is feet per minute climb rate  V2 is best one engine inoperative angle of climb speed 11 NBAA presents recommendations graphically Revised procedures example